Who has advanced their timing for more power?

[Steve@Rennsport]

Originally Posted by BLEW911

Steve@Rennsport, This post makes the most sense to me. Geting BACK to MY original question...I'm thinking a re-curved distributor would be preferbable to bumping the timing 3 degrees. Now, any recomendations for the dist. work? This is something I need to think on.

Don

Hi Don:

I can recommend Jerry Woods to recurve your dizzy or I can do that for you.

One must be conservative when using 91 octane fuels.

[Mo_Gearhead]

Steve,
Now you have my attention and I apparently need some education. I'm not that familiar with P-car distributors.

My 'old school' background (IE spring/weight distributors) tells me the vacuum advance is in place to RETARD the ignition timing in instances when the throttle is suddenly opened at lower RPM's and cylinder filling is not at its peak (to stop detonation).

Please enlighten me as to how your P-car ignition seems to work in opposition to that? Or have I misunderstood your post?

EDIT:
QUOTE "In programming chip, I generally like to keep max advance to about 27.5-28 degrees for 91 octane street gas, and about 29.5 for 93 octane fuel at the full throttle 4000-6500 rpm zone. This may be a compromise, and not deliver the maximum power on a dyno over what another chip with 33 degrees advance uses, but keeps the margin of safety I prefer."
_________
Steve , I just read this thread posted by you (it is a few years old). I'm REALLY confused now???

[BLEW911]

Thank you Steve.

Don

[Lorenfb]

"If you add it up, the total advance came to about 47-52 degrees"

Totally insane, and from a so-called tuner. NO CLUE!
Porsche "Workshop Manual 911", Volume VI, pgs 9.3-20, 9.3-21 (911SC from 1981 Model)

Another clueless one: "Yet offers NOTHING to back up his hyperbole!!"

READ THIS THREAD AGAIN! THE GREAT POSTS BY THE PRE-3.2 GUYS HAVE EXPLAINED IT FULLY:


__________________________DENTONATION_____________ _____________

[Steve W]

Really? So you're saying that the vacuum advance should be disabled then? Why would Porsche put one on if it would cause detonation?

[Joeaksa]

Originally Posted by 911 in SC

Jeesh, lighten up a little bit! All I did was ask a simple question. I've only been on Pelican a little over a year. I don't understand why you are so offended by my simple question.

Does the company listed in your signature sell 'chips' for a 3.2? Again, just a simple question. It really isn't clear on your website at all.

Mike,

LorenFB hates everyone, so not to feel bad. He hates some people worse and its coming out in this thread very nicely. I feel another "ignore" coming should he not wise up and shortly.

[Steve@Rennsport]

Originally Posted by Mo_Gearhead

Steve,
Now you have my attention and I apparently need some education. I'm not that familiar with P-car distributors.

My 'old school' background (IE spring/weight distributors) tells me the vacuum advance is in place to RETARD the ignition timing in instances when the throttle is suddenly opened at lower RPM's and cylinder filling is not at its peak (to stop detonation).

Please enlighten me as to how your P-car ignition seems to work in opposition to that? Or have I misunderstood your post?

P-car distributors use springs, weights, and the positioning of the stops, to control the advance urve, just like any other,... Some cannisters have single lines and some cannisters and some have double lines.

Intake vacuum is used to control timing in these N/A and turbocharged engines with some having vacuum advance, retard and timing retard with the onset of boost. Porsche's factory manuals display the functionality for each distributor in use and the timing curves so that is something you might find useful to read.

For N/A performance engines, we disable the vacuum controls and set it for centrifugal only.

EDIT:
QUOTE "In programming chip, I generally like to keep max advance to about 27.5-28 degrees for 91 octane street gas, and about 29.5 for 93 octane fuel at the full throttle 4000-6500 rpm zone. This may be a compromise, and not deliver the maximum power on a dyno over what another chip with 33 degrees advance uses, but keeps the margin of safety I prefer."
_________
Steve , I just read this thread posted by you (it is a few years old). I'm REALLY confused now???

That statement applies to Engine Management where there are a LOT of variables at work including throttle position, RPM, cylinder head temps, intake air temps, CR and fuel...

[Mo_Gearhead]

QUOTE: "For N/A performance engines, we disable the vacuum controls and set it for centrifugal only."
______

Ok, thats what we always did with our engines also.

QUOTE: "That statement applies to Engine Management where there are a LOT of variables at work including throttle position, RPM, cylinder head temps, intake air temps, CR and fuel"
_______

I just re-read this thread and can't understand why it got so hostile? It seems to me most of what was written agrees with the above ...and that (as I stated earlier) unless a car is equipped with enough electronics to monitor lots of 'real time' data (as you stated above) and that can change timing "on the fly"... aren't we all in agreement that one should be very cautious pushing the limit on total timing for that last one or two H.P?

[dshepp806]

A reread for me, as well,..reveals the same conclusion as Mo_Gearhead...again, for me.

Being an engineer (although not a mechanical one), I seem to see both sides' points, but modding should be approached with higher degrees of caution. I bought my 89, 3.2L in November, last year. She's bone stock and is adequate for me (not racing). If it were, I would certainly look to ALL 'squeezes' of increased HP/response (naturally)....... this part being a personal decision.

Having been on this board under a year, I've had some exposure to the dialogues between several users here when it comes to both chipping and "personalities". I really hate to see things come to that,....in engineering, there's a thing called "designing for worst case condition" (whatever that "condition" may be). For me (and my car) it's the things that can go bad if NOT done carefully, and within the right environments. Knowing little about all of the (possible) negatives,..and spending the entire frikin' weekend reading about predetonation, ignition (pre?) , combustion, the cylinder materials.....on and on,...GEEEEZ,..scared the SH*&^*^%&^t out of me,..the thought of "something going bad". Some readings (provided by gracious Pelanites) rendered MY answers to the phenoms...this resonance bandwidth of mistimed sparking or (mis) advanced timing conditions and super-related to what Loren (and some others in the industry) have stated about not knowing that a condition is, in fact, existing..............HOWEVER (and as have MANY Pelicanites have certainly noted), where are the masses of 3.2L 911 owners using present (market) chips that have experienced engine deaths? Certainly this speaks to something,..or am I frikin' crazy? This board alone would reveal some malresults,..yes? Where the hey are they?

Knowing a bit more now ( lightly,..NOT claiming to be, now, an expert [[[[[[[pleeze...]]]] ),..I would think that chipper would possibly display more data (maybe it's already there?) that demonstrates that these terrible resonances, in fact, are NOT happening,...? Not sure,.... Being a relative newbee to this, compared to other long term owners, TRUE P-wrenches and automotive consultants who hang here in this great group,..it's hard to generate highly technical questions (renderings?) until more education comes in to play (and, obviously: doing)... all of you guys' patience is appreciated. Surely I've missed many things, as there is much to learn.

Ya' know,..I eagerly look to reading the major players' posts here (characterizations aside).... To watch Grady Clay dart in with his precision of words on so many diverse areas,..or Steve (BOTH),....or Pete,...and MANY MANY others.... I really hate to see the name calling and wish that it could just disappear,..at least for a while ,..while I try to digest all information, ..........looking at the analytics of the matters at hand,..pros/cons...Thank you all for your technical statements and observations.....ALL parties should intelligently step up to the plate and LET"S """DISCUSS""""" these issues...inquiring minds (with frikin budgets) wanna' know (without the name-calling, ...I must say that Mr. Wong (for the most part) asks very poignant questions to Loren,...and these should be answered, respectfully...lot's of knowledge between these two fellows........I NEED BOTH!!!!!!!!!!!!!!!

Some of the threads have been SO heated in the past..please,..leave it be.

dammit: TEACH ME ABOUT WHAT YOU , MINUS THE Bullsh&t KNOWS!!!!!!!!!........say it in a frikin professional manner...let this crap go.....and get back to business here.

I draw no sides here...just absorbing.

How could a RUSH freak NOT paste the lyrics to a related song (by RUSH): (apply, as needed)


HALF THE WORLD (RUSH)

Half the world hates
What half the world does every day
Half the world waits
While half gets on with it anyway

Half the world lives
Half the world makes
Half the world gives
While the other half takes

Half the world is
Half the world was
Half the world thinks
While the other half does

Half the world talks
With half a mind on what they say
Half the world walks
With half a mind to run away

Half the world lies
Half the world learns
Half the world flies
As half the world turns

Half the world cries
Half the world laughs
Half the world tries
To be the other half

Half of us divided
Like a torn-up photograph
Half of us are trying
To reach the other half

Half the world cares
While half the world is wasting the day
Half the world shares
While half the world is stealing away

(ahem............................................. .....)

(truly) Best to ALL of you...

...back to "technical"....................

[RoninLB]

Originally Posted by dshepp806

...back to "technical"....................

ok



anybody know why so called hot rod curvres are related to power in a 911 carbed engine instead of the torque curve ?



i'm not asking why an advance is necesary, such as better atomization at higher rpms and faster combustion under greater power. Just that old detroit muscle cars were hot rod timmed to the torque curve and not the power output.

[Steve@Rennsport]

Originally Posted by RoninLB

ok

anybody know why so called hot rod curvres are related to power in a 911 carbed engine instead of the torque curve ?

i'm not asking why an advance is necesary, such as better atomization at higher rpms and faster combustion under greater power. Just that old detroit muscle cars were hot rod timmed to the torque curve and not the power output.

Hi Ron:

Speaking only for myself, timing tweaks are really done to improve mid-range torque & throttle response, not necessarily for more HP.

In some cases, you get both depending on the engine's configuration and fuels being used,...

[RoninLB]

thx Steve..

i have most of the basics, like even exotic FI doesn't produce more total power than carbs, etc




Even my 2.7RS dizzy curve maxes out at 5.7k instead of the lower rpm of the torque peak.. Why is my issue.

[Lorenfb]

A thread that went nowhere!

And here's why:

- S. Wong -

"So you're saying that the vacuum advance should be disabled then? Why would Porsche put one on if it would cause detonation?"

"If you add it up, the total advance came to about 47-52 degrees - YIKES!"

"I think that is why the best chips today are tuned on today's 91 octane gasonline, and even with that, there are significant margins as these cars were originaly tuned for 87 octane."

Failed to locate, read, & understand the appropriate Porsches manuals.

1. The vacuum advance/retard never affected the timing +/-8 deg.
2.Max timing per Porsche Manual is 35-38 degrees (Porsche "Workshop Manual 911",
Volume VI, pgs 9.3-20, 9.3-21 (911SC from 1981 Model) and NOT 47-52 deg.
3. The recommended octane is 96, per pg 101 of the 3.2
owners manual and pg 0.2 of the Porsche "Workshop
Manual 911 Carrera", Volume I, indicates 95-96 octane.

And by no means 87 octane!

- S. Weiner -

"For N/A performance engines, we disable the vacuum controls and set it for centrifugal only."

Hardly appropriate for street and emissions and may result in
pinging where the distributor had a vacuum retard for increasing load.

"In short, there ARE some significant gains to be found with responsible, intelligent changes to advance curves depending on the individual engine."

Right, especially when promoting sales. The typical is 3-5% at best
for advancing the timing 5-10 degrees beyond what Porsche
used, and HARDLY significant.

"Detonation thresholds in air-cooled engines are NOT static; they change with engine temps (oil and cylinder head), outside air temps, mixture, fuel quality, and load (throttle position & RPM). Further, no two engines are alike, even of the same type. Failure to take all these variables into account when adjusting ignition timing can be an expensive exercise."

This he got right.

"It takes experience to know what margins are safe and when an ignition profile is too aggressive for all the variables."

No, it takes knowledge and resources, e.g. Porsche/Bosch. That's why Porsche/Bosch used
knock sensors to max the timing under ALL conditions starting with the 964 engine.

"California is the only state with sub-acceptable octanes but some engines, notably water-cooled ones, run OK with 91, even with chip tuning. In precise term, tell me WHY they are worse in your opinion?"

The 3.2 911 required 95-96 octane. Most all states had 98 back then. Now it's difficult to find 93 especially in the west, much less anything greater. It's worse now, especially for
older cars without knock sensors. Most/all cars now have knock sensors and DON'T have
the detonation problem from the spark plug position of the air cooled 911.

"I think everyone reading this thread understands there are advance limits (without the technical details), but that doesn't preclude making certain changes under controlled circumstances by qualified personnel."

You don't have controlled circumstances without knock sensors!

- KTL -

"Of course the design engineers for the engine management systems are going to err on the side of caution to ensure the chosen timing spec may avoid detonation under the varying conditions an engine sees throughout it's lifespan."

Dream on. Most don't have the time, resources, nor engineering
knowledge that Porsche/Bosch had/has to properly tweak engines without active feedback
sensors, (knock sensors), i.e. the so called performance engineers/tuners even if they
say they've been conservative. It's difficult enough without knock sensors to properly
avoid detonation, e.g. temps, loads, various fuels, even for major OEMs with adequate
resources to max the timing for performance.

[JBO]

I just re-read it also, and though a few people asked, I still don't know if Loren sells performance chips....

[Lorenfb]

"I just re-read it also"

Maybe not with your glasses on.

[KTL]

Originally Posted by Lorenfb

A thread that went nowhere!

- KTL -

"Of course the design engineers for the engine management systems are going to err on the side of caution to ensure the chosen timing spec may avoid detonation under the varying conditions an engine sees throughout it's lifespan."

Dream on. Most don't have the time, resources, nor engineering
knowledge that Porsche/Bosch had/has to properly tweak engines without active feedback
sensors, i.e. knock sensors.

Once again you misinterpret what I write. Apparently I have to spell every single thing out for you? The design engineers I was referring to are those which you so religiously claim are the only ones who know what they're doing- the guys at Porsche/Bosch.

Oh this thread went somewhere. Same place others have gone, in which you've participated......... the crapper.

[RoninLB]

i brought up a few issues, i think?




Anybody know a good joke?

[Lorenfb]

"i brought up a few issues, i think?"

Yes, you & others, but it's too bad most don't understand it or don't care, as is obvious from their posts.

[Joeaksa]

Originally Posted by Lorenfb

Yes, you & others, but it's too bad most don't understand it or don't care, as is obvious from their posts.

Do not care that you have an attitude that takes away from any productive discussion? Well, I guess its not going to change so will just give up and let you continue to shoot yourself in the foot...

[Wavey]

Loren, you seem to REALLY need this, so here's your gold star. Now try to play nice with the other boys.